Pair creation at large inherent angles

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:33443

Chen, P; Tauchi, T; Schroeder, D V ^[1]

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1. Stanford Linear Accelerator Center, CA (United States)

In the next-generation linear colliders, the low-energy e{sup +}e{sup {minus}} pairs created during the collision of high-energy e{sup +}e{sup {minus}} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx_lt} {Upsilon} {approx_lt} 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. Since the central issue is the transverse momentum for particles with large angles, the authors notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. In this paper they reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer.

• DOE Contract Number: AC03-76SF00515
• OSTI ID: 33443
• Report Number(s): CONF-9006267--; ISBN 981-02-0931-2
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATOR FACILITIES
BACKGROUND NOISE
BEAM-BEAM INTERACTIONS
DESIGN
ELECTRON PAIRS
LINEAR COLLIDERS
PAIR PRODUCTION
RADIATION DETECTORS